On current drive in field-reversed configurations

The problem of current drive in field-reversed configurations, by apl,lying two transverse magnetic fields rotating in opposite sense: is analyzed within the framework of two-fluid collisional equations. It is shown that it is possible to generate opposite torques on electron and ions, while the net externally applied torque is vanishing. In this scenario, wall interactions, collisions with neutrals and diffusion effects are not required in order to maintain the steady stale. It is also shown that, when electrons and ions are almost in phase with the two rotating fields, the injected power is mainly dissipated by collisions associated with the azimuthal motion of both species, which should permit the achievement of significant plasma current drive efficiency in field-reversed configurations.